During recovery operations in a wellbore, different stimulation techniques may be performed downhole, including nitrogen circulation, acidizing, fracturing, or a combination of acidizing and fracturing. Acidizing and nitrogen circulation are designed to clean up residues and skin damage in the wellbore in order to improve the flow of hydrocarbons. Fracturing is designed to create fractures in the formation surrounding the wellbore to allow hydrocarbons to flow from a reservoir into the wellbore. To enable the use of these stimulation techniques, perforations, or holes, may be created in a downhole casing in the wellbore. The perforations allow acid and other fluids to flow from the wellbore into the surrounding formation. The perforations may also allow hydrocarbons to flow into the wellbore from fractures in the formation created during fracturing techniques.
Recovery operations may also include using one or more ball valves to provide control of fluids to and from the formation. The ball valve isolates the portions of the formation downhole from the ball valve to prevent fluids from flowing into the formation from uphole and prevent fluids from flowing uphole from the formation during stimulation operations performed uphole from the formation.